Acne (formally known as "acne vulgaris") is a skin disease which afflicts, in some form, approximately 80 to 90 percent of all teenagers. Acne can also affect many adults and infants. The severity of acne can range from minor skin lesions called comedones to nodules and cysts which can potentially permanently scar skin tissue.
The areas of the body that are commonly affected by acne are the face, chest and upper back. These areas of the body have a high sebaceous gland concentration which causes the skin to be oily.
Acne is believed to start with increased release of hormones in the body such as androgens. Young adults going through puberty, for instance, tend to produce more hormones such as androgens. It is believed that androgens stimulate the sebaceous glands to produce more sebum, which is an oily substance released on the skin. Sebum is a lipid-laden product comprised of a mixture of fats, waxes and fatty materials.
As more and more is produced, sebum can agglomerate and form solid plugs known as comedones in the hair follicles. Formation of a comedone, in turn, causes layers of dead skin known as keratin to accumulate and be retained within the lining of the follicles. The buildup of keratin causes hyperkeratosis of the follicular opening, which can completely close off the follicular canal.
Within the follicular canal are bacteria indigenous to the follicular lining. Included in the bacteria are anaerobic, gram positive organisms classified for instance as Propionibacterium acnes or Propionibacterium granulosum. When comedones form in the follicular opening, these bacteria feed on the sebum. Specifically, the bacteria produce lipases that hydrolyze triglycerides and release free fatty acids. The fatty acids thus generated in combination with the bacteria activate the immune system of the body causing inflammation, swelling and redness around the follicle. Depending upon the degree of inflammation, pustules, cysts, nodules, and papules may form.
In the past, many different treatments have been proposed for curing acne. Such treatments include topical keratolytic agents, topical or systematic antibiotics, or hormonal treatments designed to limit sebum secretion. Unfortunately, some of these treatments can produce adverse side affects.
Topical keratolytic agents include, for instance, tretinoin and benzoyl peroxide. These anti-acne agents prevent the blockage of follicular canals and reopen clogged follicular openings by breaking down keratin. Some keratolytic agents, however, can irritate the skin causing excessive dryness, scaling, swelling, burning, peeling, redness and allergic reactions.
Antibiotics that have been used in the past to treat acne include tetracycline, erythromycin, clindamycin, meclocyclin, metronidazole, minocycline and doxycycline. While administration of these drugs is often effective in treating acne, antibiotics have several disadvantages. For example, when taken orally, antibiotics may cause many undesirable side effects including abdominal cramps, black tongue, fatigue, depression, nausea, and other various effects. When applied topically, the antibiotics can lose their effectiveness if used for a prolonged period of time due to resistance developed by the bacteria.
The hormones estrogen and antiandrogens have also been used to treat acne in severe cases. These hormones when taken orally, however, can feminize adolescent males and can increase the risk of blood clots and cancers. Thus, hormones are rarely administered orally.
In view of the disadvantages associated with current acne treatments, a need exists for an acne preventive agent that does not create any of the above adverse side effects. A need also exists for an anti-acne agent that destroys the bacteria that causes the inflammation associated with acne.